A Systematic Review of Biomechanical Studies Utilising Finite Element Analysis in Hallux Valgus Deformity

Research Type: Level 1 - Randomized controlled trial (RCT), Meta-analysis of randomized trials with homogeneous results Introduction/Purpose: Hallux valgus (HV) is a common foot deformity affecting up to 23% of adults aged 18-65 years and 35.7% of elderly individuals over age 65. Finite element analysis (FEA) has emerged as a valuable computational tool for investigating the complex biomechanics of foot deformities. This systematic review evaluates published FEA studies investigating HV biomechanics, surgical correction techniques, and post-operative fixation methods. Methods: Following PRISMA guidelines and PROSPERO registration, we searched Medline, EMBASE, PubMed, and Cochrane Library databases from inception to September 2024. Two independent reviewers assessed eligibility, extracted data, and evaluated risk of bias using an adapted ROBFEAD tool. Included studies employed FEA to investigate HV biomechanics, with or without surgical intervention. Results: Nineteen studies met inclusion criteria (12 surgical, 7 biomechanical), involving 176 participants (79% female, mean age 49 years). All studies demonstrated moderate to high risk of bias. Biomechanical analyses revealed significant alterations in HV patients, including increased lateral metatarsal loading (40-55% higher stress), medial shift of peak pressures at the first MTP joint, and compromised first ray load-bearing capacity in patients with ligamentous laxity. Surgical technique analyses demonstrated metatarsal shortening up to 6mm could be accommodated before significantly altering foot loading patterns. Fixation studies clearly demonstrated superiority of dual fixation methods, with the MICA technique (one intramedullary and one bicortical screw) showing minimal osteotomy displacement under loading conditions. Conclusion: FEA provides valuable insights into HV biomechanics and surgical optimization. The data supports dual fixation approaches, precise osteotomy parameters, and caution regarding post-operative protocols. Future research should focus on standardizing modeling approaches, incorporating dynamic loading simulations, and patient-specific modeling to further enhance clinical applicability. PROSPERO:CRD42024605684 Example FEA model of a foot undergoing minimally invasive hallux valgus surgery demonstrating the model breakdown into discrete elements